pparatus twice over; and in almost every shop emergencies
are constantly happening in which a good blowpipe will render most
efficient service. Small brazing work can often be done in less time than
would be consumed in going to the smith's hearth and back again,
independently of the policy of keeping a man in his own place, and to his
own work. The shrinking on of collars, forging, hardening, and tempering
of tools, melting lead or resin out of pipes which have been bent, and
endless other odd matters, are constantly turning up; and on these, in the
absence of a blowpipe, I have often seen men spend hours instead of
minutes. Things which need a blowpipe are usually most awkward to do
without one; and men will go fiddling about and tumbling over each other
without seeing really what they intend to do. They are content, as it all
counts in the day's work; that it comes off the profits is not their
concern. It will, perhaps, be new to many of you that blowpipes can easily
be made in a form which admits of any special shape of flame being
produced. I have made for special work--such as heating up odd shapes of
forgings, brands, etc.--blowpipes constructed of perforated tubes formed
to almost every conceivable shape; these being supplied with gas from the
ordinary main and a blast of air from a Root's or foot blower. I have here
an example of a straight-line blowpipe made for heating wire passed along
it at a high speed. The same flame, as you no doubt will readily
understand, can be made of any power and of any shape, and will work any
side up; in fact, as a rule, a downward vertical or nearly vertical
position is usually the best for any blowpipe. As an example of this class
of work, I may instance the shrinking on of collars and tires, which, with
suitable ring-burner and a Root's blower, could be equally heated in five
minutes for shrinking on; in fact, the work could be done in less time
than it would usually take to find a laborer to light a fire. When the
rings vary much in size, the burners can easily be made in segments of
circles. But then they are not nearly so handy, as each needs to be
connected up to the gas and air supply; and it is, in practice, usually
cheaper to have separate ring burners of different sizes. Of course, you
will understand that a 1/2-inch gas-pipe will not supply heat enough to make
a locomotive tire red hot, and that for large work a large gas supply is
necessary. Our own rule for burners of